“Earth-Like Planet” Gliese 581g May Not Actually Exist

Remember Gliese 581g, the Earth-like planet whose discovery scientists announced two weeks back, saying it could potentially sustain life? Bad news: Not only were the initial reports that “the chances for life on this planet are 100 percent” overblown; now, new data suggests that the planet may not actually exist.

Steven Vogt, the researcher who led the team that announced the Gliese 581g discovery (and the utterer of the now-infamous “chances for life on this planet are 100 percent” line, which he clarified was a statement of personal belief rather than of scientific evidence), based his discovery on a mix of his work at Hawaii’s Keck Observatory and previously published data.

But the publishers of that old data used by Vogt, who collected it using Chile’s High Accuracy Radial Velocity Planet Searcher (HARPS), have come out with new data which lacks evidence for Gliese 581g.

HARPS statement is stronger than “we don’t see it” – they find that if they force a solution they get a negative signal appearing, implying the planet is not there, not just that they are not sensitive to it.

This initial lack of evidence for the planet’s existence doesn’t yet prove that it doesn’t exist, and a definitive conclusion one way or the other may be a ways off: Such are the difficulties of determining the existence of a planet 20 light-years away based on minute fluctuations, much less surmising that that planet does or doesn’t contain life. But it certainly puts a damper on things, especially if HARPS’ statement is indeed “stronger than ‘we don’t see it.’” Yet again, a reminder that before we get swept up by the triumphal popular science claims of the press, the science-science claims need to be on firm footing, and that’s no small feat.